New EQUA ‘NCAP for NOx emissions’ test ranks real-world car pollution

Emissions Analytics has launched the first fully independent index-based NOx emissions standard for cars and the UK firm claims the new EQUA Index provides a level playing field “to help clear the confusion over real world NOx emissions”.

The new EQUA Air Quality Index has been developed from Emissions Analytics’ existing real-world car economy test. Purely assessing NOx (nitrogen oxide) emissions, it gives a simple score from A to H for all cars tested.

An A rating means a car meets current NOx limits for diesel and petrol cars: an H rating is worse than even the very oldest Euro emissions standard – equivalent to 12 times the current Euro 6 limit. The ratings are explained in full below.

Alarmingly, more than 50 older Euro 5 diesels scored an ultra-dirty H rating, along with three current-standard Euro 6 cars – and a supposedly-green diesel-hybrid model, the Peugeot 3008 Hybrid4, was also given a worst-possible H rating.

The EQUA Air Quality Index has been launched with ratings for 440 vehicles and the firm has vowed to test 200-400 new cars each year to ensure the rankings are as up-to-date as possible.

Nick Molden, CEO and founder of Emissions Analytics, said: “There’s a great deal of confusion among car buyers on the subject of pollutant emissions, but we’re able to deliver impartial and precise information to help them buy better.

“We’re also looking forward to working with the industry as a whole to highlight the best vehicles available.”

EQUA Air Quality Index: the winners and losers

Volkswagen Group cars are the big winner of the EQUA Air Quality Index tests. A batch of its latest Euro 6 diesels have been tested – and of the six cars assessed, all six have achieved the very cleanest A-rating, suggesting tailpipe NOx emissions are exactly what Volkswagen claims in real-world use.

Proof that no defeat devices are active on the latest models..?

The BMW 3 Series also achieved an A-rating for real-world Euro 6 diesel emissions – the only other Euro 6 diesel to do so: of the 62 latest-spec cars tested, three scored B-ratings, 9 were rated C, 13 were rated D, a worrying 20 were rated E, five scored F, two G and three the very worst H rating.

In contrast, all but four of the 45 Euro 6 petrol cars tested were rated A, suggesting the latest diesel models in particular have an issue with hitting Euro 6 NOx targets in real world use. All diesels, that is, except Volkswagen Group diesels…

Every single Euro 6 hybrid vehicle also achieved an A-rating.

As for Euro 5 diesels (which were applicable for new cars in showrooms up until September 2014 for newly-launched models and September 2015 for existing on-sale in-market motors), things are far worse.

Not a single Euro 5 diesel car scored an A-rating, or a B-rating: the best model was the Skoda Octavia 1.6-litre TDI, with a C-rating. Then it was five D-rated cars (proving Euro 5 cars can only meet Euro 4 limits), followed by a staggering number of E, F, G and H-rated cars.

However, all but eight of more than 100 older Euro 5 petrol cars tested failed to score the very lowest A-rating for NOx emissions. Does this mean air quality campaigners are right to focus on getting older diesel models off Britain’s roads?

“Over half London’s NOx from vehicles comes from Euro 1-3 PETROL cars……There has been a rise in acrid NH3 with increased use of Hybrids.” DEFRA reports 2014

The same report condemns 20 mph zones – they are worse for all pollutants than 40 mph zones. Hardly surprising given basic physics that increased traffic flow is what allows diffusion and engines run far more efficiently outside of stop start zones.

The big increase in urban NOx is in part due to a supersize me consumer culture where all cars and especially SUVs and Crossovers are sold on safety. Yet these vehicles are on average far larger and heavier than any previous cars. They have to force more air out of the way at speed, they reduce traffic flow on UK’s narrow streets by preventing filtering at T junctions, and effectively block roads when parked on curbs. They create less space for cyclists. Being tall and slab sided (like buses and trucks) there is less fresh air around cars in stop start traffic.

The other side of the story is Govt reducing roads from dual carriageways into single lanes and slowing it down with speed humps and 20 mph zones. Flow is reduced when large car drivers lack spaial awareness and can’t get past a cyclist or in rural areas tractors leading to long jams and higher pollution.

The DEFRA reports note that early 2000 to 2005 diesels cars have far lower NOx emissions. Even so much NOx comes from industry and heating of homes and offices. But this is a complex world: reducing urban NOx actrually increases Ozone which is another problem for asthma sufferers.

Pollution is national and international not just street side. A change to EVs will not prevent the worst pollution days on record – High Atmospheric Pressure, Light Easterly airflow from continent sends back UK’s normally exported pollution often mixing it with dust from North Africa. Pumping out more emissions from power stations and running heavier than diesel PHEVs will make matters worse quite apart from the higher embedded environmental costs of making new cars over retaining older ones.

The answer is something like River Simple !

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